The present invention relates to couplings and, more particularly, to spindle couplings of the type used in connecting a powered prime mover to the rolls of a rolling mill or connecting the pinion stand to the rolls, as well as to like apparatus.
The usual type of spindle coupling presently employed in rolling mill practice includes a coupling sleeve at each end of a spindle shaft. The coupling sleeve at one end connects drivingly to a prime mover or pinion stand and at the other end to the spade end of a roll in the rolling mill.
When it is necessary to change a roll in a mill, the roll is withdrawn from the roll-end coupling sleeve and a new roll is inserted into the coupling sleeve.
When the roll is withdrawn, the coupling sleeve, acting under the influence of gravity, tends to sag and thereby become misaligned axially with the spindle. The coupling sleeve is so misaligned that it is difficult to insert the roll spade end thereinto unless the coupling sleeve is raised by applying an external force to it, which is costly and time consuming.
U.S. Pat. No. 2,845,781 shows and describes a form of universal coupling of the type used for connecting together a rotary prime mover, or the pinion stands associated therewith, and the rolls of a rolling mill. The coupling shown includes an annular stop ring 51 that is secured by studs 52 to the end of the casing 24. An inwardly projecting portion 53 axially extends toward the hub portion 33 and, in service, is spaced apart therefrom a short distance. When the roll end is withdrawn from the casing, the internal spring urges the projecting portion 53 to engage with the hub portion 33 and thereby keep the casing in axial alignment with the spindle.
Further, those skilled in the art will recognize that the spindle coupling of U.S. Pat. No. 2,845,781 exerts thrust forces on connected machinery bearings which can lead to the failure of such bearings.
However, those skilled in the art will recognize, from the following description of the embodiment of the present invention shown in the drawing, that an aligning thrust force acts continually between the hub and a thrust ring, and axial movement of the roll relative to the spindle does not result in axial movement of the coupling sleeve. Also, no thrust is imposed on connected thrust bearings and no bearing failures can result from axial thrust forces.